(1) Field of the Invention
The present invention relates to photodetectors such as image sensors, and more specifically to color filters provided to photo-cells in a photodetector.
(2) Description of the Related Art
A commonly used photodetector includes a semiconductor substrate having a plurality of photo-cells, and each photo-cell is provided with a color filter and a photodiode. There are red color filters (R), green color filters (G), and blue color filters (B) in one photodetector, and each photo-cell is assigned with a color filter having one of the three colors. The photodiodes generate signal charges responsive to the intensity of the light that has passed through the color filters. Consequently, a signal charge for light of a specific color in the incident light is generated in each photo-cell. Imaging data for one picture is generated by collecting the signal charges for the three colors generated in the photo-cells (See Japanese Laid-Open Patent Application No. H05-006986, for example).
Conventional color filters are usually manufactured by mixing acrylic resin with pigments or dyestuff of respective colors (See Japanese Laid-Open Patent Application No. H07-311310, for example).
Manufacturing the conventional color filters, however, requires a troublesome material management for the pigments or dyestuff of different colors in the manufacturing process, and this hinders the cost reduction of the photodetectors.